Category: Administration / Server

GNU Linux ssh magic tricks – reverse ssh tunnel – open source admin’s vpn and teamviewer replacement (no open ports needed) – how to use ssh into a network behind router-firewall and forward port of any device to localhost

scroll down to: “how to access user-dev-admin’s home network boxes from anywhere via reverse-ssh-tunnel! :D” ssh tunnel remote deviceD’s port access a device’s port that is only available via a specific machine 😀 or in other words: ssh-tunnel port of […]

GNU Linux howto ssh sshd config hardening security guide

ssh can be regarded as “critical core infrastructure” time spend on it’s security is time well spend time + money well invested: current manpage: WARNING: this howto guide IS MOST LIKELY INCOMPLETE! WARNING! WHEN RUNNING THE SCRIPT: […]

GNU Linux howto – enable (very detailed) logging logs log postgres database + monitor script

#!WARNING! THIS WAS TESTED FOR OLDER RHEL7 AND CENTOS! # manual editing vim /var/lib/pgsql/12/data/postgresql.conf; # postgres main config file # semi-automatic editing via sed # optional: postgres: enable detailed logging POSTGRES_MAIN_CONFIG=”/var/lib/pgsql/12/data/postgresql.conf” sed -i ‘s/#log_statement = [^”]*/log_statement = ‘all’/g’ $POSTGRES_MAIN_CONFIG sed […]


this might sound trivial, but there are multiple approaches: # for (theoretically every) Debian, but not every Debian based system: cat /etc/debian_version 11.3 # for Debian 10 and prior hostnamectl|grep Op Operating System: Debian GNU/Linux 10 (buster) # for Debian […]

SAS connected NVMes aka Kingston’s datacenter capable (24-7) NVMe SSDs (DC 1500m Enterprise-class U.2 PCIe NVMe Gen 3.0 x4 SSD) only work with mainboard that have U.2 interface – U.2 on Desktop is called mini-SAS or SFF-8643 on Servers

IDE, SCSI, SATA, SAS now U.2 M.2… these drives are called: “U.2 PCIe NVMe” no kidding, search for em on ebay. that reminds of… “the usb cable chaos” has arrived with “Slim SAS” for another round of mass cable connector confusion […]

Sony vs the internet (in this case dns resolvers)

and: is the EU / Germany location simply unattractive for many companies in view of the data protection craze? “In the end, it may be bitter for Quad9 that they only got into the trouble by moving to Europe, where […]